http://blog.csdn.net/ixidof/article/details/6638066
內存泄漏檢查方法(for Linux)
如果你更想讀原始文檔, 請參考glibc info的"Allocation Debugging" 一章 (執行info libc);
glibc提供了一個檢查內存泄漏的方法, 前提是你的程序使用glibc的標准函數 分配內存(如malloc, alloc...):
1. 在需要內存泄漏檢查的代碼的開始調用void mtrace(void) (在mcheck.h中有聲明). mtrace為malloc等函數安裝hook, 用於記錄內存分配信息. 在需要內存泄漏檢查的代碼的結束調用void muntrace(void).
注意: 一般情況下不要調用muntrace, 而讓程序自然結束. 因為可能有些釋放內存代碼要到muntrace之后才運行.
2. 用debug模式編譯被檢查代碼(-g或-ggdb)
3. 設置環境變量MALLOC_TRACE為一文件名, 這一文件將存有內存分配信息.
4. 運行被檢查程序, 直至結束或muntrace被調用.
5. 用mtrace命令解析內存分配Log文件($MALLOC_TRACE) , (mtrace foo $MALLOC_TRACE, where foo is the executible name) ,如果有內存泄漏, mtrace會輸出分配泄漏內存的代碼位置,以及分配數量. 其他東西
1. 可以將mtrace, muntrace放入信號處理函數(USR1, USR2), 以動態地進行內存泄漏檢查控制.
2. mtrace是個perl代碼, 如果你對符號地址與代碼文本的轉換感興趣, 可以讀一下.
3. again, 盡量不要用muntrace()
For C++ Leak:
檢查內存泄漏的方法除glibc提供外還可以試試一些專用的程序；如：
ccmalloc(http://www.inf.ethz.ch/personal/biere/projects/ccmalloc/ccmalloc-english.html)
mpatrol(http://www.cbmamiga.demon.co.uk/mpatrol/)
這倆個工具的功能相當不錯，能對程序進行相當全面的檢查
很奇怪，redhat 9 居然不帶mtrace perl腳本，只好下載gcc源碼編譯了
wget --passive-ftp ftp://rpmfind.net/linux/redhat/9/en/os/i386/SRPMS/glibc-2.3.2-11.9.src.rpm
rpm -ivh glibc*.src.rpm
cd /usr/src/redhat/SPECS/
rpmbuild -ba glibc-9.spec
cd /var/tmp/glibc-2.3.2-root/usr/bin/
cp mtrace /usr/bin/
調試方法如下:
vi a.c
- 1 #include <mcheck.h>
- 2
- 3 int main()
- 4 {
- 5 mtrace();
- 6 malloc(10);
- 7 malloc(16);
- 8 return 0;
- 9 }
$gcc -g a.c #記得編譯帶-g調試選項
$export MALLOC_TRACE=a.log
$./a.out
$unset MALLOC_TRACE #記得執行完后unset變量,否則可能運行其他命令可能覆蓋log
$mtrace a.out a.log
Memory not freed:
-----------------
Address Size Caller
0x09b08378 0xa at /XXX/a.c:6
0x09b08388 0x10 at /XXX/a.c:7
可以看到,會顯示未釋放動態空間的代碼具體位置.
MTRACE(3) Linux Programmer's Manual MTRACE(3)
NAME top
mtrace, muntrace - malloc tracing
SYNOPSIS top
#include <mcheck.h>
void mtrace(void);
void muntrace(void);
DESCRIPTION top
The mtrace() function installs hook functions for the memory-
allocation functions (malloc(3), realloc(3) memalign(3), free(3)).
These hook functions record tracing information about memory
allocation and deallocation. The tracing information can be used to
discover memory leaks and attempts to free nonallocated memory in a
program.
The muntrace() function disables the hook functions installed by
mtrace(), so that tracing information is no longer recorded for the
memory-allocation functions. If no hook functions were successfully
installed by mtrace(), muntrace() does nothing.
When mtrace() is called, it checks the value of the environment
variable MALLOC_TRACE, which should contain the pathname of a file in
which the tracing information is to be recorded. If the pathname is
successfully opened, it is truncated to zero length.
If MALLOC_TRACE is not set, or the pathname it specifies is invalid
or not writable, then no hook functions are installed, and mtrace()
has no effect. In set-user-ID and set-group-ID programs,
MALLOC_TRACE is ignored, and mtrace() has no effect.
ATTRIBUTES top
For an explanation of the terms used in this section, see
attributes(7).
┌─────────────────────┬───────────────┬───────────┐
│Interface │ Attribute │ Value │
├─────────────────────┼───────────────┼───────────┤
│mtrace(), muntrace() │ Thread safety │ MT-Unsafe │
└─────────────────────┴───────────────┴───────────┘
CONFORMING TO top
These functions are GNU extensions.
NOTES top
In normal usage, mtrace() is called once at the start of execution of
a program, and muntrace() is never called.
The tracing output produced after a call to mtrace() is textual, but
not designed to be human readable. The GNU C library provides a Perl
script, mtrace(1), that interprets the trace log and produces human-
readable output. For best results, the traced program should be
compiled with debugging enabled, so that line-number information is
recorded in the executable.
The tracing performed by mtrace() incurs a performance penalty (if
MALLOC_TRACE points to a valid, writable pathname).
BUGS top
The line-number information produced by mtrace(1) is not always precise: the line number references may refer to the previous or following (nonblank) line of the source code.
EXAMPLE top
The shell session below demonstrates the use of the mtrace() function
and the mtrace(1) command in a program that has memory leaks at two
different locations. The demonstration uses the following program:
$ cat t_mtrace.c
#include <mcheck.h>
#include <stdlib.h>
#include <stdio.h>
int
main(int argc, char *argv[])
{
int j;
mtrace();
for (j = 0; j < 2; j++)
malloc(100); /* Never freed--a memory leak */
calloc(16, 16); /* Never freed--a memory leak */
exit(EXIT_SUCCESS);
}
When we run the program as follows, we see that mtrace() diagnosed
memory leaks at two different locations in the program:
$ cc -g t_mtrace.c -o t_mtrace
$ export MALLOC_TRACE=/tmp/t
$ ./t_mtrace
$ mtrace ./t_mtrace $MALLOC_TRACE
Memory not freed:
-----------------
Address Size Caller
0x084c9378 0x64 at /home/cecilia/t_mtrace.c:12
0x084c93e0 0x64 at /home/cecilia/t_mtrace.c:12
0x084c9448 0x100 at /home/cecilia/t_mtrace.c:16
The first two messages about unfreed memory correspond to the two
malloc(3) calls inside the for loop. The final message corresponds
to the call to calloc(3) (which in turn calls malloc(3)).
SEE ALSO top
mtrace(1), malloc(3), malloc_hook(3), mcheck(3)
COLOPHON top
This page is part of release 4.07 of the Linux man-pages project. A
description of the project, information about reporting bugs, and the
latest version of this page, can be found at
https://www.kernel.org/doc/man-pages/.
GNU 2015-03-02 MTRACE(3)